IgE allergy testing utilization: next steps from a provincial quality improvement initiative

Appropriate utilization of allergen specific IgE (sIgE) testing is essential for optimizing identification of clinically relevant allergens. A provincial quality improvement sIgE utilization project in Alberta, Canada was recently implemented, including discontinuation of allergen screens and panels. Herein, we performed in-depth analyses of sIgE testing patterns and results after the utilization changes to identify opportunities for further improvement.

Two years of provincial sIgE data were analyzed to assess positivity by number of orders per encounter, frequency of individual sIgE orders by allergy specialists and non-allergy specialists, distribution of result values by provider group and patient age, and degree of overlap for similar allergens ordered together.

Non-allergy specialists are not substantially more likely to get at least one positive result when up to five allergens are ordered per patient encounter. Non-allergy specialists ordered more eggs, dairy and grains sIgE than allergy specialists for the same number of encounters and were more likely to receive quantitatively lower results. The frequency of detectable sIgE was much lower for adults as compared to pediatrics across all food categories except for crustaceans. For salmonid fish, crustaceans, and house dust mites, a single test per category would identify 95% or more of cases with at least one detectable sIgE.

Discontinuing allergen screens and panels is an important first step in the quest for improved sIgE utilization, but restricting the number of tests ordered per patient encounter and curating the list of available sIgE to non-allergy specialists may further optimize sIgE testing appropriateness.